Arkham Asylum

You are a villain Joker and you ended up in the infamous Arkham Asylum once more. Now you have to escape like every time before. This time you will be escaping through the underground and you will dig yourself out of the asylum. Advance trough levels until you are out. Collect all the power tools on your way. Knock out orderlies, guards and rats by using a power up or pick up and drop an obstacle on them. Once the guards find out you are out they will be all over you. You advance if you clear all the opponents or dig out all the dirt.
Also check out some more joker games here.